This invention relates to the conditioning of space in building structures and the like, and specifically to both cooling and heating thereof. The system disclosed herein is a heat pump that advantageously employs a Peltier Effect Diffusion Still (PEDS) in combination with a Steam-Jet Refrigeration Unit, a Condenser, and an Evaporation-Absorber Unit. These components are associated in a system or apparatus put into operation primarily by the application of electrical energy and assisted by the application of solar energy or other available waste heat in engine exhaust; with circulation pumps and control valves for the general object of providing a multi-purpose Chiller-Heat Pump having selective modes of operation, namely; (1) Simultaneous Low Temperature Heating and Cooling; (2) Cooling; (3) Heating; and (4) Simultaneous High Temperature Heating and Cooling. A cooling tower is employed in the cooling mode, and heat exchangers apply heat to a weak absorbent from the strong absorbent as the refrigerant is fed to and emitted from the PEDS. In practice, water is the refrigerant and calcium chloride, or lithium bromide or the like is the absorbent.
The generator means G or absorbent concentrator employed herein is a Peltier Effect Diffusion Still or PEDS, an electrically operated regenerator that drives water from the absorbent in solution therewith. In general terms the generator is a thermoelectric still which includes a series of concentric endless walled sections which sections are closely spaced and between which a series of thermoelectric elements are positioned as heat pumps. Means are provided for the passage of distillate along the radially outer surface of each of the concentric sections. Water vapor is diffused from the thin film of liquid passing along the outer surface of each section, across a narrow gap or endless space to the inner surface of the next adjacent concentric section which serves as a condensing surface. The heat for the diffusion of the water vapor at a predetermined constant temperature is provided by thermoelectric heat pumping from the first concentric section relative to the axis of the apparatus in series radially outward to the most distant section from the axis. Diffusing water vapor is thus evaporated and condensed respectively from one section to another requiring only the current necessary to pass the heat flux from the inner to the outer surface. Means are provided for removing the distillate from the inner surface of the concentrator sections and the effluent strong absorbent water from the outer surface of the respective concentric sections. Reference is made to the structure of such a Peltier Effect Concentrator Still as it is disclosed in my U.S. Pat. No. 3,393,130 dated July 16, 1968, and in my subsequent U.S. Pat. Nos. 3,671,404 dated June 20, 1972 and 3,801,284 dated Apr. 2, 1974.
In accordance with the present invention, in order to achieve the temperature differential between the evaporating surface and condensing surface of the apparatus, a thermo-electric heat pump is utilized in the form of thermo-electric elements known to the art and described in texts as "Semiconductor Thermo-elements and Thermo-electric Cooling" by A. F. Ioffe, Info Search, Ltd., 1957, and in various patents such as U.S. Pat. No. 2,959,017 Gilman, et al., "Heat Exchangers Employing Thermo-electric Elements for Heat Pumping," issued Nov. 9, 1960, and U.S. Pat. No. 2,978,875, Lackey, et al., "Plural Stage Thermo-Electric Heat Pump" is a device utilizing Peltier phenomenon of heat absorption and heat dissipation at junctions between bodies having different thermomotive properties, which phenomenon occurs when electric current is passed through the bodies. A number of junctions are coupled and generally employed in a heat pump of this type, the couples being physically and electrically interconnected to form a thermo-electric array. A thermo-electric element of the type employed in connection with the present invention typically comprises an N-type thermo-electric element and a P-type thermo-electric element. The N- and P-type components are made from semiconductor materials used in thermo-couples. An example of N-type material is an alloy of bismuth-telluride and bismuth-selenide having a formula of 75% Bi.sub.2 Te.sub.3 -25% Bi.sub.2 Se.sub.3. An example of P-type material is an alloy of bismuth-telluride and antimony-telluride having the formula 25% of Bi.sub.2 Te.sub.3 -75% Sb.sub.3 Te.sub.3. Semiconductive components including antimony and bismuth have been found suitable for use respectively as P- and N- type materials. Such materials or the formation of thermo-electric pumping elements are not claimed as novel per se in the present invention, but an example will be set forth of the type of such element employed in connection with the apparatus of the present invention.
The steam jet refrigeration means R employed herein is a fluid pressure apparatus that operates through the application thereto of primary high pressure steam used to energize an ejector that induces a secondary fluid in the form of vapor drawn from an evaporation chamber. The primary motive steam is expanded through a converging-diverging nozzle to velocities of the order of 1200 meters per second (4000 fps.). The corresponding nozzle pressure is very high, and the high velocity steam issuing from the nozzle entrains the water vapor leaving the suction-evaporation chamber, and the two streams merge in a mixing section that converges in the direction of flow. Such an arrangement is diagrammed in the drawings. Warm water return is sprayed into the evaporator chamber and the chilled water is withdrawn therefrom and utilized for space conditioning as shown herein.
The Condenser means C is shown as a conventional surface condenser that extracts heat from the booster ejector exhaust of the aforesaid steam-jet refrigeration means; an essential to operation of said refrigeration system.
The evaporator-absorber means A or absorption chiller-heater employed herein operates to continuously absorb refrigerant vapor from an evaporator, in this instance supplied with chilled water from the aforementioned steam-jet refrigeration means R. Refrigerant liquid is sprayed over the evaporator so as to pick up latent heat as it vaporizes, thereby chilling water circulated within tubes and thus yielding chilled water. Simultaneously, concentrated solution and refrigerant vapor combine in the absorber and form a diluted solution while heat is generated. This absorbing action is cooled by water coming from a cooling tower, or an alternate source as will be described, and leaves to pick up heat from the condenser C and/or the heated conditioned space. Such as chiller-heater is diagrammed in the drawings.
It is an object of this invention to advantageously combine and relate the aforementioned means G,R,C and A with circulation means and control means whereby the aforesaid distinct modes of operation are made possible as circumstances require. Operation of the generator means G is dependent upon a D.C. power supply and made effective by a feed water supply of weak absorbent continuously pumped thereto. Operation of the steam-jet refrigeration means R is dependent upon the high temperature-high pressure output of said generator, and relies upon the condenser means C to reduce temperature and pressure for use in the evaporator absorber means A. And, said means A is interdependent upon the output of each of said means G,R and C, and from the fooling tower T and conditioned space as well. The selected use of the chilled water through the means R and evaporator of the means A, and of the heated water through the absorber of the means A condenser means C is by pump and/or valve means as will be described to controllably determine the modes of operation as may be desired.